Discussions are still ongoing regarding the plastering work in residential villas that do not have a basement. The plaster is continuously sprayed with water for a period of at least seven days. During this time, the electrician runs the (conduits) attached to the concrete to route electrical cables from the main distribution panel—which will later be installed on the interior of the house’s exterior wall—until these cables reach the sub-distribution panels (subpanels) on each floor, where these conduits are routed toward the designated location for the main distribution panel. It is advisable to use conduits of at least medium thickness to prevent them from being damaged or broken during the process of burying and backfilling the foundation.
It is preferable to prepare and hire a specialized contractor to carry out the foundation insulation work immediately after the water-spraying period has ended, as will be discussed later. The project contractor also calculates the amount of backfill to be supplied to the site so that a contractor can be found to supply it. It is preferable to use fine red sand and avoid clay soil or soil filled with stones and construction debris, as we often see, andunfortunately seen in some projects. The goal of early preparation is to avoid delays in project completion and to have the opportunity to find the best prices.
At the same time, all openings (gaps) located beneath the foundation slab—between the foundation blocks—are sealed. The purpose of sealing these openings is to prevent backfill from escaping in the future, which could contribute to subsidence of the villa’s floor. After that, the entire project site is cleaned inside and out, and all debris—including wood, stones, and other materials—must be removed.
Next, a waterproofing layer is applied to the foundation from the inside and outside to protect it from moisture, salts, and water, if present. The waterproofing is applied on the interior, leaving a 12-centimeter gap at the top that is not coated, as a concrete screed will later be poured for the villa’s floor, The foundation is also coated on the outside, leaving a 30-centimeter strip uncoated, as this area will be plastered along with the facades or clad with stone or marble. It is preferable to use hot asphalt that is melted over a fire.
Readers" Questions:
After pouring the ground floor ceiling, areas with water seepage and leaks were noticed. How should this be addressed?
It is normal for seepage or water leaks to appear on the concrete after the slab is poured, and this has no impact during the concrete curing phase, since concrete is not inherently waterproof. The final ceiling—which is the first-floor ceiling in residential villas and the roofs of outbuildings exposed to the elements—is treated by installing a comprehensive waterproofing and thermal insulation system (waterproofing and thermal insulation) covering the entire surface properly before beginning the tiling work. This is of the utmost importance, and the task should be entrusted to a specialized insulation contractor at the time of contracting, as the value and importance of waterproofing in such climates—where heavy rains are common, as is the case in Riyadh—cannot be overstated. As for the ground floor and basement ceilings, they are not waterproofed at all, with the exception of bathrooms and kitchens only.
